Ribbon shifting mechanism



March 2 1943. E. BORDONARO 2,312,314

RIBBON SHIFTING MECHANISM Filed Feb. 14, 1941. 2 Sheets-Sheet 1 .5VINVENTOR 7 Y floluiolz an;

ATTORNEY March 2, 1943. L. E. oRbo'NARo 2,312,314

' RIBBON SHIF'IIIINGH MECHANISM 'Filed F eb. 14, 1941 2 Sheets-Sheet 2ATTORNEY Patented Mar. 2, 1943 RIBBON SHIFTING MECHANISM Lucian EmmanuelBordonaro, Rochester, N. Y., assignor to American Telephone andTelegraph Company, a corporation of New York Application February 14,1941, Serial No. 378,912

6 Claims.

' This invention relates to printing mechanisms s'uch'as typewriters,teletypewriters and the like, and relates more particularly to amechanism for automatically shifting a ribbon in such a manner as toincrease the life thereof.

In typewriters and teletypewriters as at present designed the typingmechanism consisting of a-set of type bars, and a platen carrying thepaper upon which printed characters are to be struck, are moved relativeto each other as successive characters are printed, and in order toprint the character a ribbon is interposed between the type bar and thepaper on the platen as it strikes upon the latter. This ribbon inaccordance with the present practice is struck at a given point in itswidth, and each successive character strikes the ribbon at the samerelative position as respects its upper and lower edges. In other words,if one character strikes the ribbon in the middle, all of the otherswill strike the ribbon at its middle, although at successive pointsalong its length. The result is that the entire wear on the ribbon asthe ribbon is graduallyfed back and forth in front of the striking placeis all concentrated upon one horizontal level, and the portions of theribbon above or below this level are unused. This concentration of thewear along one line shortens the life of the ribbon.

It is the purpose of the present invention to cause an automaticshifting up and down of the ribbon as it is moved relatively to theplaten so that successive characters Will strike the ribbon at differentpoints of its Width.

More specifically considered, an object of the invention is to so designa typing machine that, with relative movement between the type carriageand the platen from left to right'during the typing operation, the pointon the ribbon where the type pallets strike shifts from one edge of theribbon at the start of a line across the page to the other edge of theribbon at the end of the line.

The invention will now b'e'mor'e fully understood from the followingdescription thereof when read in connection with the accompanyingdrawings, in which Figure 1 shows a slide bar along which the mechanismwhich holds the ribbon at its striking point moves as the type carriageis shifted relative to the platen; Fig; 2 is a side view partly insection showing the relationship between elements of the type carriageand the platen; Fig. 3 is a front view of the platen showing how theslide bar is related thereto; Fig. 4 is a side view partly in section ofa detail showing how the rlbbon'is supported and shifted'as the ribboncontrolling mechanism passes along the slide bar;

Fig. 5 is a cross-section of the slide bar; Fig. 6 is a plan view withparts broken away of the ribbon controlling mechanism shown in Fig.4,together with a ribbon spool cup, the figure showing how the ribbon iswound upon a spool asjit is gradually shifted with respect to theposition on the platen at which a type bar impinges against the ribbonto print a character; Fig; 7 is a figure showing the relative positionsof the p1'aten,ribbon and type bar during the printing of letters orlower shift characters; Fig. 8 is a similar view showing the positionsof these elements during the printing of figures or other upper shiftcharacters; and Fig. 9 is a view showing a strip of ribbon with dottedlines indicating how the level at which the various characters areprinted shifts from'top to bottom of the ribbon in accordance with theinvention.

Referring to Fig. 2, l designates a portion of the frame of the typecarriage of a teletypewriter. On'the rear of this frame a roller2 isprovided which rolls upon a rear carriage track 3 extending from side toside between sections of the main frame of the teletypewriter, so thatthe type carriage may roll back and forth from side to side to printsuccessive characters on a sheet of paper carried by the platen, andthen return to start a new line. A front roller 4 is mounted on a lug 5carried by a side extension 6 of the main frame of the type carriage.This roller 4 rests upon the front carriage track 1 extending from sideto side of the main frame (not shown) of the teletypewriter. Two ofthese rollers are provided to keep the type basket level on its track.By rolling along the front and rear carriage tracks the rollers 2 and 4enable the type carriage mechanism to be shifted from side to sideduring the operations of typing a line and returning the carriage. Itwill be understood, of course, that these rollers are not essential butmay be replaced by sliding surfaces.

Type bars such as 8 are provided with toothed segments cooperating witha rack upon the upper rear surface of pull bars such 'as'9. The rearends of the type bars and the pull bars are mounted in transverse slotsradially cut in an arcuate-shaped type bar segment l0 mounted upon sidebars of the main frame I. A longitudinal groove in the type bar segmentl0 carries a bearing rod ll likewise bent in the form of an arc so as tofit in the arc-shaped longitudinal groove of the type bar segment Ill. 7This bearing rod serves as a bearing about which the type bars 8 maypivot as they are moved to strike the platen I2, when a given one of thepull bars such as 9 is moved to the right.

The ends 9' of all the pull bars normally rest upon the upper surfacesof a set of code bars I3. These code bars have notches (not shown) intheir tops, and are capable of transverse movement with respect to theends of the pull bars in accordance with various code combinations. Eachcode combination brings one of thenotches in each of the code bars I3into alinement with corresponding notches of other code bars, so thatthe end 9' of the pull bar can drop into the alined notches. The pullbar thus selected drops down so that a shoulder 9" engages the pull barbail I4 which is attached to arpulh'ba'r :bail plunger l5 movablebetween twolroller guides I 6 and I1. After the pull bar is selected, arocker arm I8 is actuated to move in a clockwise direction, and by itsengagement with the. roller 19 carried on the underside of the plungerI5, the

plunger and the pull bar bail -I 4-are moved from left to right, therebyshifting the selected pull bar-from left 'to right. The pull-barthroughits toothed "engagement with the'T-type banswings "thecorresponding ftype bar about thebe'aring rod I I,-so that therengagingfa'ce'of thetypebar will strike against the platen 12. The spring 20restores "the pull bar to its normal position'wh'en the -rocker arm' I8returns inia counterclockwise direction to its normal position.

The platen I2 is mounted 'b'etw'eenside frame members 21 which arearranged to swingabout a pivot 22 under the centroid a lever '23 therebyshifting the platen I2 .up and down: from-its Ii'letters position" toits figures positionand .vice

'versa. In Fig; l -the"pla'ten"I-2 'is'shoWn-fin its letters position.The sheet "of paper 24 .upon which the printing operationtakesplace'iscarfled over a guide 25 and passes around theplaten I2'between' theplaten :and the-rollers 26 and 21,

" finallypassing outof the machine under :the

tear-plfbar 28. A ribbon spool "cup 29 is-mount- '"ed' 'upon the typebar "carriage by-e'lernents'not shown and carries 'aiTlbbOH'SDOOY 30. Astyping 'takes' place the'ribbon 3i .is'fed from thisspool I step by stepbetween "thepaper' 24 andatype bar such as 8,"whichis being "operatedto'type the I character.

The mechanism by which the ribbon 3 I .is"carried'in'frontof"thefpl'aten isbetter shown in Figs.' 4 and 6. From these views it'willv'beseen that the -ribbon '3I"is':fed'from the spool 30"and "passesaround a*rod"32"and through'guides 33 and 340ia'ribbonfshi'eld"35'carried'by a ribbon shield support 36.After'passing' through the ribbon shield, asabove described, the ribbonis wound upon"another "spool (not shown).

*The ribbon'shieldiisprovided with members 311' and 38-whichengagawitharms and) carried "by a ribbon shield guide 4 I mounted *upon'tsomesuitable element of the frame (not shown).

Atits lower end the support 36 for the ribbon shield is pivotallyattachedat 42 to a ribbon oscillator lever 43. Said lever 43 :ispivotedat 44 to theend of '-a -ribbon shift lever -44, which is pivotedat-45'toa suitable-portion of the frame 46 of the type carriage.

The ribbon shift .lever 44' carries'a roller4'I which-rests beneath aslide bar 48 mounted between the side framesllof .theplaten, as shown inFig. .3. Bymeans of a coiled spring '49 the ribbon 'shift'lever 44' is"to"theplaten', the roller 4! bearing on the under- Jside of the slidebar 48 as the type carriage moves step by'step during successive typingoperations.

- the tension' of the spring 49.

down to the rear of 2. lug 5! carried by the pull bar bail plunger I 5.

The ends 52 and 53 of a spring coiled about the pivot 44 tend tomaintain the levers 43 and 44' in the position shown in Fig. 4. Thelever 44' is held from rising further by means of the engagement of theroller 47 with the slide bar 43. The lever 43 is prevented from swingingfurther upwardly about the pivot 44 by the engagement or the lever 58carried thereby with the lug or stop 5! on the plunger I5. This holdsthe ribbon 3| in the position shown in Fig. 4. Theentire ribbon shiftand controlling mechanism shown in Figs. 4 and 6 is movable laterally as"the type carriage shifts laterally with respect By means of this ribboncontrolling mechanism the ribbon is caused to be shifted up and down-under several. different conditions. 'Forexam- -ple, during eachprinting operation the ribbon 31!, whichis normally held in the positionshown in Fig. 4, "so that it will be below the character last printedand thus willpermit the operator to see the printed charactersonthe'paper, is shifted upwardly to bring the ribbon between the'type 3bar and the platen.

This is accomplished through the agency of the pull barbail plungerI5-which ismoved fromleft to right in Fig. 4 each time a'printingoperation takes place. As "the lug 5| carried-by the plunger I5 moves tothe right, the lever'5ll under the pressure'of the spring arm52 followsthe lug 5| 1.35.

to the right, and this causes the ribbon'oscillator lever'43 toswingupwardly about its pivot 44 and thus raise the ribboninto theprinting position, the ribbon being pulleddown again to display the typecharacter when the plunger I5 is returned 40.

.. ribbon shift lever 44' remains stationary with the to itsnormalposition. During this-action the roller-41 resting'against the slide bar48 under This operation takes place each tirnea character'is printed.

There is alsoanother condition under which the ribbon -3I is shifted upand down. -As'is well known, type bars, such as 8 inFigs. '7- and 8, areprovided with upper and lower case characters 54 *and'55. For printingletters or other 1 lower case characters the platen I2 will be in theposition shown inFigsJZand 7, so that when the ribbon 3| is shiftedupwardly during the printing operation, as described in the previousparagraph,'it will lie between the lower case type 55 "and the platen.Consequently'when'the platenis struck the character 55 will be printedon the sheetoftpaper24. Under these conditions the character'54will notengage either therihbon 3Ior'the platen I 2.

When it isdesired to print an uppercase charactenthe' side frame 2|carrying the platen I2 (see Fig.2) :is shifted upwardly about thepivot22 by the lever 23, so that the printing point of "the platen is broughin front of the upper case character-54 as shown in Fig. 8. Asthe-platen l2 swings up to this position, the slide bar 48 iscorrespondingly elevated in the following manner. -As'the roller 4'!follows the slide'bar'48upwardly,-the"lever 44 swings about the pivot'45under the'pull'of the spring 49 and carries :the

' 'ribbon oscillator lever '43 upwardly with "it. The "latter issubstantially prevented from --swinging around its pivot 4Iby theengagement ofxthe-lever fifl with-the' lugil 'on the plunger 15. Thiselevation of 1evers'44 'and 43 causes the ribbon -aeiasie 3|, as shownin Fig. 8, t be elevated to a point between the upper case character 54and the platen.

This action takes place each time there is a shift from lower case toupper case, and the fulcruming action of the levers '43 and44 are sorelated that printing in the upper case position takes place atsubstantially the same position between the two edges of the ribbon forboth upper and lower case printing. For example, as shown in Figs. '7and 8, the characters are'printed in both cases near the upper edge ofthe ribbon 3|. In other words, as shown in Fig. 9 the engagement of thetype with the rib-bon 3| will be along the dotted line 56. As is wellknown, the ribbon is slowly unwound from one spool and wound up on theother, thus passing through the ribbon shield 35 by short steps eachtime a character is typed. The mechanism for thus shifting the ribbon iswell known, and is not herein shown as it forms no part of the presentinvention. 1

As earlier stated, it is desirable that instead of having the typestrike the ribbon along a single line parallel to its edges somearrangement be made whereby the type at various times will strike atvarious places not only along the length of the ribbon but up and downbetween the upper and lower edges thereof. This is accomplished inaccordance with the present invention by having the underside of theslide bar 48 tapered as shown in Figs. 1 and 3. Consequently the roller41 moves along the slide bar as the type carriage is stepped from leftto right during the operations of printing a line of type,

' and the lever combination 43, 44' swings about the pivot 45 with theright-hand end of lever 43 (see Fig. 4) gradually shifting downward asthe roller 48 is forced downward.

The result of this is that at the beginning of a line the ribbon will bein the elevated dotted line position shown in Figs. 4, '7 and 8 at thebeginning of the line, and will gradually be shifted downwardly to itsfull line position when the roller M arrives at the right-hand orthickened end of the slide bar 48. successive characters are impressedagainst the ribbon and the ribbon isfed through the ribbon shield, thesucessive points of contact between the type and the ribbon may runalong a diagonal line such as 51, as shown in Fig. 9.

For example, the first character may be printed at the level indicatedby 58. The next character, assuming that the ribbon is gradually beingstepped from right to left for each typing operation will strike theribbon at the right and a little above 58, and so on until the last typestrikes the ribbon at the point 59. The carriage is then restored to itsinitial position to print a new line. This immediately shifts the ribbonto its dotted line position as shown in Figs. 4, 7 and 8, and the nextline starts at point fill. The ribbon is successively struck by the typealong the line 6| with the result that the last character typed willstrike the ribbon at point 62 and so forth.

Finally as we approach the end of the ribbon, or in other words, thepoint at which the ribbon reverse mechanism (not disclosed) causes theribbon which is now wound up on one spool to be unwound and shifted tothe other spool, another action takes place. Let us assum that near theend of the ribbon the type is successively striking the ribbon along theline 63, and at 64 the carriage is returned and the type then commencesstriking along the line 55 until the point 66 is reached. Let us assumethat just at the point In consequence, as the 66 the ribbon reversemechanism comes into play and causes theribbon to feed through theribbon shield from left to right. The direction of typing along theribbon being now reversed, the successive typing points will travel frompoint 66 along the diagonal line '6'! until the point 68 is reached atthe end of the line. Here the carriage is return-ed and the typing alongthe ribbon commences at 69 and follows along the line If) to point I I,etc.

.Thus it will be seen that the type strikes the ribbon along linesextending on a bias with respect to the ribbon itself, and these linesare pitched oppositely as the direction of movement of the ribbon isreversed. There is, therefore, a greater spread of the type impressionson the ribbon as shown in Fig. 9. However, as the ribbon is successivelyfed back and forth, the positions of these'diagonal lines are graduallyshifted along the length of the ribbon, due to the stretching of theribbon, to the different degrees of tautness at which it is wound uponthe spool, and to other unpredictable mechanical factors. Thisultimately results in the entire area of the ribbon between the line 56and the line extending through the points '58, 60, etc., being struck bythe type at Various times. The effect is as though the diagonal lines51, 6 i 63, etc., gradually shifted to the right or to the left withsuccessive reversals of the direction of feeding of the ribbon. The wearand tear upon the ribbon is accordingly distributed over an entire areainstead of over one line 56, with the result that the ribbon will lastmuch longer.

It will be noted that the distance between the line 56 and the linepassing through points 58, (iii, etc., is much greater than the verticaldistance that the roller 41 is moved up and down as it rolls along theinclined part of the slide bar 48. Thisincrease in the distance coveredon the ribbon is due to the fact that the lever combination 43, 44',pivoting about point 45 with the fulcrum at the edge of the roller 41,has a magnifying action with respect to the end 42 of the lever 43, andcauses a much greater vertical traverse of the ribbon than the verticaltraverse of the roller 61.

If desired, the slide bar, in addition to being tapered longitudinally,may also be tapered along its width to vary its thickness along the line12, as shown in Fig. 5. By so doing, when the platen moves from lettersto figures, it raises the slide bar 48 upwardly and the roller 47 movesalong the surface 12. This combined shift action results in a movementof the ribbon equal to that of the platen, due to the compensatingeffect of the tapering along the width of the slide bar as shown at 12in Fig. 5.

It will be obvious that the general principles herein disclosed may beembodied in many other organizations widely different from thoseillustrated without departing from the spirit of the invention asdefined in the following claims.

What is claimed is:

1. In a typing mechanism, a platen, typing means to type charactersagainst said platen, said platen and typing means being movablelongitudinally with respect to each other as successive characters areprinted, a type ribbon, means to gradually feed said ribbonlongitudinally with respect to the point at which the type strikes saidplaten, a longitudinal member lying parallel to said platen, said memberhaving a tapered sur face, and lever means riding upon said taperedsurface to gradually shift said ribbon in a vertical planefassaid-iplateniandtyping means movewith respect toeachtotheraduringtheprinting of each line of characters; therebyspreading. -thewear' of the ribbontdue to the impactof pri'ntingover awider area thereof.

2. In a typing mechanism, "a platen, typing means to type "characters"against said platen, said platen"andt yping means being movablelongitudinally with irespectto each other as successive characters areprinted, a type ribbon, a ribbon shield to hold: said =ribbon' inposition with respectto said platen; means to gradually feed said ribbonlongitudinally through said shield with 'respectto the pointuatzwhichthe type strikes said platen, a longitudinal member lying parallel tosaid platengsaidm'ember having a tapered surface, means toshift'saidishield in a vertical plane 'in changing from uppercase tolower case printing, 'saidmeans including lever means riding upon saidtapered surface to gradually shift said ribbon in a verticalplaneas-said platen and typing means move withrespect to each otherduring the printing of each line 'of characters, thereby spreading the:wear'of the ribbon due to the impact of printing "characters over awider area thereof.

3. Ina typing mechanism, a platen, typing means to type charactersagainst said platen, said platen and -.typing-means being movablelongitudinally-with respect to each other as successive characters are"printed, a type ribbon, a ribbon shield to'ho'ldsaid ribbon in positionwith respect to said platen, means to gradually fee-d said ribbonlongitudinally through said shield with respect to the pointat which thetype strikes said'platen; a-longitudinal member lying parallel to saidplaten, said member having a tapered surface, means to :shift saidshield in a vertical plane to remove the ribbon from over the printedcharacter as each' character isprinted, said means including lever meansriding upon said tapered surface togradually'shift said ribbon in avertical plane as said platen-and typingmeans move with respect toeach-other during the printing of each line of characters, therebyspreading the wear of the ribbon-'due'to the impact of printingcharacters over a wider area thereof.

4. In a typing :mechanism, a platen, typing means to typecharacters-against said platen, said platen and typing means beingmovable lcngitudinallvwith respect'to each other as successivecharacters are printed, a type ribbon, a ribbon shield to hold saidribbon in position with respect to said platen,"means to gradually feedsaid ribbon "longitudinal-1y through said shield with respect to thepoint-at which the type strikes said platen, a longitudinal member lyingparallel to said platen, said member having a tapered surface,'aleverhaving said tapered surface as its fulcrum, means operating :said'lever to shift said shield in a vertical plane in changing from uppercase to lower case printing, said lever operating as its fulcrummovesalong said tapered surface to gradually shift said ribbon in avertical plane as said platen and typing means move with respect to eachother during the printing of each line of characters, thereby-spreadingthe wear of the ribbon due to'the impact of printing characters overa'wider area.- thereof.

5. In a typing mechanism, a platen, typing means totype charactersagainst said platen, said platen and typing means being movablelongitudinally with respect to each other as successive characters areprinted, a type ribbon, a ribbon shield to hold said ribbon in positionwith respect to said platen, means to gradually feed said ribbonlongitudinally through said shield with respect to the'point at whichthe type strikes said platen, a longitudinal member lying parallel tosaid platen, said member having a tapered surface, a lever having saidtapered surface as its fulcrum, means operating said lever to shift saidshield in'a vertical plane to remove the ribbon from over the printedcharacter as each character is printed, said lever operating as itsfulcrum moves along said tapered surface to gradually shift said ribbonin a vertical plane as said platen and typing means move with respect toeach other during the printing of each line of characters, therebyspreading the wear of the ribbon due to the impact of printingcharacters over a wider area thereof.

6. In a typing mechanism, a platen, typing means to type charactersagainst said platen, said platen and typing means being movable withrespect to each other'as successive characters are printed, a typeribbon, a ribbon shield to hold said ribbon in position with respect tosaid platen, means togradually feed said ribbon longitudinally throughsaid shield with respect to the typing point on said platen, a levermovable about a fulcrum to shift said shield in a vertical plane inchanging from upper case to lower case printing, said fulcrumcomp-rising a tapered slide bar along which said lever is moved assuccessive characters are printed, said slide bar being inclined withrespect to the plane of movement of the platen and typing means withrespect to each other, whereby the fulcrum of said lever is graduallychanged to cause said lever to gradually shift said ribbon in a verticalplane during the printing of each line of characters to spread the wearof the ribbon due to the impact of printing characters over a wider areathereof.

LUCIAN EMMANUEL 'BORDONARO.

